Transmission Fluid Leaking problems of the 2016 Chevrolet Silverado 1500

Rpm increases between 4 and 5. 5k but unable to acceleration after descension from hill while driving on I-17. It appears my transmission/gears slip following hill descents. On 6 occasions, while driving to and from moab, utah on Aug 9-10, the engine revs up to 4. 5 - 5. 5k at the bottom of the hill/decline. I could not get out of the gear or pick up speed upon acceleration. Braking did not stop the revs. I just kept my foot off the brake and accelerator until the gear eventually kicked in. Otherwise the truck ride and drive is amazing and no other problem except getting annoying gear clunks now and then, every since I purchased it. Back in 2017 midway chevy said that is not a problem. Well, I drove my truck for the first time yesterday since the incident. The problem reoccurred while descending a very small hill in anthem. This time span was much shorter. I want to mention that I have driven my truck up I-17 from anthem, az to flagstaff and beyond at least 20 times in the last 4 years and never experienced this. I do not have a floor mat or anything on the driver side floor of the truck. There are no signs of trans fluid leaking (on garage floor etc. ), no way to check my trans fluid level. No messages showed up in the dic (driver info ctr), or on the dashboard instrument cluster (message center) (I. E. : transmission, speed, service brake assist, etc. ), no diagnostic warning and the August monthly diagnostic report did not reflect any problems. I don't think any features were accidentally turned on while driving (I. E. : tow/haul, hdc, grade braking etc. ) . The problem continued after turning truck off and restarting, which should disengage most features. I am a 70 year old woman and haven;t driven the truck hard or never hauled anything. I am 2k miles out of warranty. Will never pay 53k for a vehicle with such a lousy drive-train warranty.